Conventionally, as a surgical knife used in surgical operations, there have been known two types that a handle portion to be grasped when used and a blade edge portion at the front end of the handle portion are formed integrally, and that a knife blade and a holder are formed separately while the knife blade is attached to the front end of the handle when used. The latter type of knife such that the handle and knife blade are manufactured and supplied separately and incorporated when used is widely used. When such a knife is a knife for work, the knife blade is exchanged with a new knife blade according to the wearing state of the blade edge. Meanwhile, when such a knife is a surgical knife, the knife is used as disposal equipment while a used knife blade is discarded and exchanged with a new knife blade. Conventionally, in the case where a knife blade is attached to an attachment portion such as a slit or the like provided at the front end portion of the holder body grasped when used, a user holds a knife blade with one hand and fingers to attach, while holding the attachment portion of the holder body to fix using the other hand and fingers or using a device such as a forceps or the like.
However, since the surgical knife is formed particularly acutely, there is a risk of injury such as hurt and the like when the surgical knife is attached or detached, and it is required to attach and detach the surgical knife safely and easily. Therefore, in the case of the surgical knife, for example, Patent Document 1 proposes a structure where a case-shaped guard is provided in a surgical knife blade, and fitted and attached to a handle, and the internal knife blade is caused to protrude outside the guard with an operational slider provided on the handle side when the surgical knife blade is used after being attached. Accordingly, the guard with the internal knife blade is attached and fixed to the handle to be used, and the knife blade is removed from the handle together with the guard and discarded after being used. The publication describes sterilizing the guard to distribute, and thereby preventing infection when the guard is attached to the handle and used.
Patent Document 1: JP 2003-504145